This invention is directed to improvements in rigid barrels generally used for the shipment and storage of a great variety of commercial and industrial materials such as fuels, lubricants and solvents, and particularly to sealing assemblies and methods for joining two detachable half sections of such barrels, wherein each such half section is in the shape of a frustrum having its larger end open and its smaller end closed.
In the shipping industry the recycling of metal barrels of the type commonly used for shipping and storing materials is limited by the costs of returning empty barrels to a supplier and reconditioning used barrels for reuse. Since conventional barrels cannot be disassembled, collapsed or otherwise reduced in size, an empty barrel occupies the same volume as a full one, thus the cost of shipping such a barrel back to its source for recycling is prohibitive. Also, such metal barrels must be cleaned, derusted, degreased and repainted before they can be used again, and because of the inaccessibility of the interior of such a conventional barrel which may only be reached through a bung hole in the barrel head, this reconditioning is a costly and time comsuming process. Since the aforementioned expenses are nearly as great as the cost of a new barrel there is little economic incentive for users of such barrels to recycle old barrels to conserve valuable materials.
A solution to the aforementioned problems of recycling old barrels is provided by collapsible barrels comprising a pair of detachable half sections, each in the shape of a frustrum having its larger end open and its smaller end closed, and a sealing assembly for joining the two larger, open ends of the two half sections tightly together, as is shown for example in the aforementioned U.S. patent application Ser. No. 255,597 for COLLAPSIBLE REUSABLE BARREL FOR FLUIDS, herein incorporated by reference. Such collapsible barrels may be broken down and nested to save space for shipment, and to permit ease of access to their interiors for reconditioning.
A somewhat similar package is shown in Herrington U.S. Pat. No. 1,390,784 which discloses the use of two frustrum-shaped half sections, each having its smaller end closed and its larger end open with an outwardly projecting flange formed around its larger end. In Herrington the larger, open ends are joined together to form an assembled package by bolting the respective flanges of the two half sections together, which requires a great deal of time and limits the location of the sealed fasteners to specific points around the periphery of the package thereby concentrating the force restraining the two half sections from separating at certain points around the periphery of the package which increases the likelihood of breakage at those points and the likelihood of poor sealing at the points where the force is not so concentrated.
Sinclair U.S. Pat. No. 295,295 also shows a somewhat similar butter package which utilizes two half sections each of which is closed at one end and open at the other, and which are joined together at their open ends. The sealing assembly of Sinclair includes a pair of outwardly projecting flanges formed around the respective open ends of its half sections wherein the flanges have respective corresponding thick and thin portions, and a pair of C-shaped buttons which are placed over the thin portions and moved along the flanges peripherally around the package over the thick portions to seal the half sections together.
While the Sinclair package may be sealed more rapidly than the aforementioned Herrington package, the C-shaped buttons must be finally placed over the flanges at specific points around the periphery of the package where the flanges are sufficiently thick to force the two half sections together, otherwise the sections would be too loose and the buttons would fall off thereby completely breaking the seal of the package. The number of such specific points which may be provided is limited because of the need for thin portions of the flanges as well as thick portions in order to place the C-shaped buttons over the flanges, and because the slope of the change from a thin portion to a thick portion must be gradual enough that the buttons do not bind thereon. As a result of this limitation the restraining force is concentrated at such specific points which produces the aforementioned detrimental results described with respect to the Herrington patent. In addition, any tangential force applied to a button, as is likely to occur during handling of the package, will tend to move the button toward a thin portion of the flanges which will cause it to become loose and degrade the seal.
Therefore, it can be seen that there is a need for a method for assembling a collapsible, reusable barrel utilizing a seal which permits the barrel to be rapidly assembled and disassembled yet distributes the restraining force evenly around the periphery thereof and which resists tangential forces that may occur during handling of such barrels. Also, in order to protect the contents of such barrels from theft and vandalism which frequently take place, particularly in international shipping, it is important to provide such barrels with a sealing assembly which may not be broken by hand.